AFCAD (Advanced Fuel Cells for Aviation Decarbonisation)
Funder
Aerospace Technology Institute
Value
£1.2m
Team
Oliver Curnick
Ian Bates
Vinoth Mohanraj
Leanne Parrott
Lead: ZeroAvia
Duration
Feb 2024 – June 2026
Overview
The AFCAD (Advanced Fuel Cells for Aviation Decarbonisation) Project will bring zero-emission, hydrogen-electric propulsion to large, 2-5MW aircraft applications. Zero-emission propulsion at that scale is uniquely enabled by ZeroAvia's high temperature polymer electrolyte membrane (HTPEM) fuel cell stack technology, which will be scaled from 20kW
modules to ~100kW modules at TRL5 by the end of the project.
AFCAD will focus on research, build, test and evaluation of stack technologies (bipolar plates (BPP), membrane electrode assembly (MEA)) and their integration into a stack, with four main metrics being improved: Power Output, Specific Power, Efficiency and Durability.
These technologies will be taken from TRL 3 to TRL 5 by sophisticated test campaigns of components and systems in collaboration with Coventry University, the University of Kent and the University of Bristol. In addition to that, the University of Sheffield's Advanced Manufacturing Research Centre (AMRC) and ZeroAvia will establish the manufacturability of the components, and an assessment and establishment of the required supply chain.
Coventry University's role within the project focuses on ground testing of fuel cell MEAs and stacks at 2kW scale, to validate design and verify performance against power density targets under a broad range of operating conditions.
CU will be designing and building a bespoke, 2 kW-scale HTPEM stack test bed, featuring advanced electrochemical diagnostic capabilities to evaluate the origins of fuel cell efficiency losses under different operating conditions and control strategies.
CU will design and execute a programme of accelerated stress tests (ASTs) at single cell and short stack scale to probe the effects and interactions of various fuel cell degradation modes. Data from these tests will inform the development of a detailed, data-driven stack degradation model, capable of predicting the likely lifetime of a fuel cell stack under an
aerospace duty cycle.
Objectives
CU will develop accelerated stress tests (ASTs) in consultation with Zeroavia (ZA) to activate specific degradation modes relevant to aerospace duty cycles and operating conditions.
CU will develop and/or adapt their single-cell PEMFC test stand to evaluate ZA's next-gen MEAs, applying ASTs and advanced electrochemical diagnostic techniques to gain a detailed understanding of MEA performance and durability.
CU will conduct long-term durability tests on ZA short stacks covering up to 7,500
hours of operation.
CU will adapt their existing measurement and instrumentation system for performing spatially-resolved impedance spectroscopy (EIS) measurements in ZA's HTPEM hardware, and will assist ZA to replicate this measurement capability in-house.
CU will contribute to project dissemination activities through publication in academic journals and presentations at international conferences.
Impact
To date, academic research into hydrogen fuel cell performance and degradation has typically focused on small-scale single-cell fuel cells (e.g. 25-50 cm2 active areas). These studies have explored individual degradation modes for LTPEMFCs such that their mechanisms are now well-understood. However, less attention has been given to the study of higher temperature HTPEM technology at full-scale cells and stacks (several hundred cm2 active cell area, and stacks of hundreds of cells), where additional effects such as non-uniform current, temperature and reactant distributions may give rise to different, more complex behaviour not captured by existing models.
Current fuel cell technology trends are towards larger electrode active areas in pursuit of higher stack power densities required in emerging applications - aerospace in particular. Research into the implications of these larger electrode areas for performance and durability is therefore required urgently in order to inform optimal design of stack hardware and broader control systems and strategies. In the AFCAD project, Coventry University will develop a 2kW scale short-stack test bed with advanced diagnostic capabilities capable of elucidating the detailed performance and degradation characteristics of application-scale HTPEMFC stacks.
We will also develop instrumentation and measurement system for making spatially-resolved electrochemical impedance spectroscopy (EIS) measurements on HTPEM stacks. With the agreement of project partners, we will make redacted data from this test bed available on an open-access basis via a CU-hosted repository. Such data will prove useful to other academic groups carrying out research and teaching activities around PEMFC stacks and systems, with the potential to improve the general understanding of performance and degradation in large-format PEMFC stacks.
The short stack test facility will also prove valuable to any academic groups looking to evaluate their technology developments at applicationscale stack level, offering a convenient platform to trial new materials and components prior to scale-up. The test bed design will itself be documented and disseminated via journal publications and conference presentations.
By making such designs available to the academic community, we will encourage the in-house fabrication of advanced, bespoke test beds by other academic groups.
